If You will remove your windows efi partition by mistake, this method could help You. It will work only, if rest of Windows partitions are OK.
You will need:
- another Windows machine
- USB drive
Go to another windows machine and copy EFI folder (contains Microsoft folder and rest of important files inside). Around 20 MB. Probably you will need to temporary assign letter to that partition.
Copy mentioned files to your /boot/efi partition.
In my case it looks like that:
Add Windows boot entry - edit /etc/grub.d/40_custom and add:
insmod part_gpt insmod fat set root='hd0,gpt2' if [ x$feature_platform_search_hint = xy ]; then search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint- efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2 UUID else search --no-floppy --fs-uuid --set=root UUID fi chainloader /EFI/Microsoft/Boot/bootmgfw.efi
hd0,gpt2 - it is your efi partition
UUID of your efi partition
You need to prepare Windows recovery usb, Windows installation usb is also OK if you have one.
Go to another windows machine, open control panel and type "recovery".
Chose upper option and prepare usb drive.
Boot using your new USB and choose:
- Advanced Options
- Command prompt and type:
Scanning all disks for Windows installations. Please wait, since this may take a while... Successfully scanned Windows installations. Total identified Windows installations: 1  D:\Windows Add installation to boot list? Yes<Y>/No<N>/All<A>:
Confirm and you are done.